SMART SENSOR AR816+ Digital LCD Anemometer Handheld Wind Speed Meter Air Speed Tester   Features: 1. Wind speed & temperature measurement. 2. Wind chill indication. 3. Temperature display in Celsius or Fahrenheit. 4. Different wind speed measurement unit including m/s, Ft/min, Knots, km/h, Mph.   5. Measure wind speed in: Current/Average/ Max. 6. Low battery warning. 7. LCD backlight . 8. Auto / Manual power off.    Wind Speed Measuring  0.3~45m/s                                                     Wind Speed Accuracy    ±5%  Wind Speed Units  m/s,Ft/min,Knots,km/h,Mph   Current/Average Measuring  yes  Temperature Measuring Range  -10°C~45°C  Temp. Resolution   0.2℃  ℃/℉ Selection  ---  Backlight Display   yes  Low Battery Indication   ---  Data Hold Function   yes  Resolution   0.1m/s  Max & Min Measuring   Max only  Range Bar Graph   yes  Wind chill indicaton       yes  Auto/Manual Power Off  yes  Power   CR2032 3.0V (not included)  Product Net Weight / Size     58g / 110*43*21mm  Packing Contents:                                                      1pc anemometer ,  1pc user's manual,  1pc blister package            Operation Guide:  1. Put battery into battery compartment, LCD will blink all display for a second.  2. Recover battery door, push" MODE "in 1s to turn on the unit. LCD will display wind speed, temperature & battery icon. LCD backlight will lasting for12s.  3. Setting different wind measurement: Push "MODE"for 3 seconds until"m/s" starts to blink. Push" SET "to select desired measurement unit. To confirm     the desired measurement unit by push" MODE ". Digit symbol:m/s meter per second; km/hr kilometer per hour; ft/min feet per minute; knots nautical mile      mph mile per hour; Cu Current wind speed, MAX max wind speed, average wind speed.  4. ℃/℉ switch option:Press the little conceal key on the rear cabinet to select different temperature unit  5. Press any key will active LCD backlight for 12 seconds.  6. Measurement: when the wind vane ( impeller ) turns, LCD will instant display wind speed and temperature. When temperature  below 0℃,      wind chill symbol will shown on the LCD.  7. Push MODE+SET to turn off the unit.  8. Build in 14 mins auto off Remark: Temperature switch key ( ℃/℉) conceal in the rear cabinet, pls use a little pushpin to press the key for ℃/℉ conversion.   Wind speed / temperature measurement range:    Unit  Range  Resolution  Accuracy  ℃  -10℃~+45℃  0.2  ±2℃  ℉  14℉~113℉  0.36        ±3.6℉  Current consumption  About 3mA       Weight       52g (including battery Weight and langyard)  Battery      9V Battery (not inlcude )  Wind speed range  Unit         Range   Resolution  Threshold        Accuracy      m/s  0~45  0.1  0.1  ±5%